1. Field of Invention
This invention relates to a method and apparatus for application of powder coatings and, more particularly, the application of powder coatings or dustings to extrusions, sheet materials, thin films, piece parts and various other items without release of the dusting material into the atmosphere.
Manufacturers, such as extruders, use dusting to speed up their manufacturing process. When material exits the extruder, it is hot and tacky. Dusting is used to coat the extruded material so that it can be quickly moved to the next phase of the manufacturing process without having to wait for the material to cool. Examples of this include car moldings, wiper blades, seals and the like. In addition to extruded products, there are many other manufacturing operations that use dusting as part of their manufacturing process. Quite often the powder coating for dusting are talcum or cornstarch and can be used on rubber, silicon, plastic, bread, wire extrusions and the like.
All of the powder coating or dusting systems heretofore used have had difficulty providing uniform coatings and are invariably "dirty", releasing large amounts of dusting particles into the atmosphere which is a direct violation of Environmental Protection Agency regulations. These "dirty" dusting systems waste large amounts of powder and require additional and costly safeguards for employees as well as other plant equipment.
2. Concise Explanation of Prior Art
There is no known prior art that functions in a manner similar to the present invention.